SETTING:

PARTICIPANTS:

MAIN OUTCOME MEASURE:

Number of medications prescribed in each visit and specific medication combinations.

RESULTS:

There was an increase in the number of psychotropic medications prescribed across years; visits with 2 or more medications increased from 42.6% in 1996-1997 to 59.8% in 2005-2006; visits with 3 or more medications increased from 16.9% to 33.2% (both P < .001). The median number of medications prescribed in each visit increased from 1 in 1996-1997 to 2 in 2005-2006 (mean increase: 40.1%). The increasing trend of psychotropic polypharmacy was mostly similar across visits by different patient groups and persisted after controlling for background characteristics. Prescription for 2 or more antidepressants, antipsychotics, sedative-hypnotics, and antidepressant-antipsychotic combinations, but not other combinations, significantly increased across survey years. There was no increase in prescription of mood stabilizer combinations. In multivariate analyses, the odds of receiving 2 or more antidepressants were significantly associated with a diagnosis of major depression (odds ratio [OR], 3.44; 99% confidence interval [CI], 2.58-4.58); 2 or more antipsychotics, with schizophrenia (OR, 6.75; 99% CI, 3.52-12.92); 2 or more mood stabilizers, with bipolar disorder (OR, 15.46; 99% CI, 6.77-35.31); and 2 or more sedative-hypnotics, with anxiety disorders (OR, 2.13; 99% CI, 1.41-3.22).

CONCLUSIONS:

There has been a recent significant increase in polypharmacy involving antidepressant and antipsychotic medications. While some of these combinations are supported by clinical trials, many are of unproven efficacy. These trends put patients at increased risk of drug-drug interactions with uncertain gains for quality of care and clinical outcomes.